The present invention relates to an improved electric connecting element for piezoelectric plates and particularly to an electric connecting element adopted for use on an input end of the piezoelectric plates to facilitate installation and achieve good electric connection.
At present the methods of establishing electric connection between a piezoelectric plate 10 and a circuit board 20 can be grouped in the following types:
FIG. 1 illustrates one type of electric connection in which the connection spot 12 for either the high voltage output end or the power supply input end of the piezoelectric plate 10 is directly soldered through a leg 30 or 40. As the piezoelectric plate 10 is subject to shaking when conductive, especially the shaking of transverse frequency, the legs 30 and 40 are prone to fracture. Moreover, connection done entirely by soldering is a tedious and troublesome operation. The space required for shaking is restrictive and limits its performance.
FIG. 2 shows another type of electric connection. It mainly has the legs 30 and 40 bent to form integrated electric connection plates 50. Each connection plate 50 is bent to form an elastic section 51 corresponding to the electric connection spot 12. For installation, the piezoelectric plate 10 is wedged in and the elastic section 51 provides an elastic force to anchor the piezoelectric plate 10 to establish electric connection. The elastic force of the elastic section 51 also provides a desired shaking space for the piezoelectric plate 10 to maintain its effectiveness. However, shaking of the piezoelectric plate 10 may occur in the longitudinal direction in addition to the transverse direction. Clipping by the smooth surface of the elastic section 51, the piezoelectric plate 10 is easy to get loose or break away under excessive shaking. To remedy this drawback, some tries to shorten the distance between the elastic sections 51 of the two connection plates 50. But such an approach creates a risk of fracturing the fragile piezoelectric plate 10. Moreover, such a design also is dubious in terms of practicality.
FIG. 3 depicts yet another type of electric connection that has a housing box 60 to hold the piezoelectric plate 10. It has a plurality of legs 61 connecting to the piezoelectric plate 10 and a plurality of cushion units 62 coupling with the legs 61 to constrain the piezoelectric plate 10. As the piezoelectric plate 10 is located in the housing box 60 and connected to the legs 61 and retained by the cushion units 62, the shaking generated by the piezoelectric plate 10 may be absorbed and eliminated by the cushion units 62, and the legs 61 may be prevented from fracturing. While such a design can resolve most of the problems occurred in applications, the housing box 60 and its lid 70 take a greater amount of space. It does fit very well for electronic products that demand a smaller size.
Therefore the primary object of the invention is to resolve the aforesaid disadvantages. The invention provides an improved electric connecting element that has an elastic section connecting to an electric connection spot of the input end of a piezoelectric plate. The elastic section has one end extended to form an anchor section to fasten to a circuit board and another end extended upwards above the piezoelectric plate to form a retaining section to prevent the piezoelectric plate from shaking loose from the electric connection spot of the piezoelectric plate. Thus the piezoelectric plate may have a better electric connection and also may be held securely without breaking away under excessive shaking.